CHROMATOGRAPHIC, SPECTROSCOPIC, TOPOGRAPHIC, AND X-RAY CRYSTALLOGRAPHIC STUDIES OF THE SOLID-SOLUTION FORMED BY RACEMIC 3-CARBOXY-2,2,5,5-TETRAMETHYL-1-PYRROLIDINYLOXY (3-CARBOXY-PROXYL)

The solid solution formed by the title compound, C9H16NO3, has been ex amined by a variety of techniques and shown to be an equi-molecular mi xture of the two enantiomers. Refinement of the disordered structure w as based on the orthorhombic space group Pnma with a = 8.023(2), b = 1 0.030(3), and c = 12.352(2)Angstrom, final R = 0.055, The oxygens of t he carboxyl group are disordered and both enantiomers can occupy the s ame, rather than alternate, crystallographic sites, Results from studi es involving IR, GC-MS, and chiral chromatography are also presented. In addition we report on the use of synchrotron X-ray topography to in vestigate strain in crystals of the solid solution.